+PKG_CHECK_MODULES(LIBUNWIND, libunwind,
+ [have_libunwind=yes], [have_libunwind=no])
+if test "x$have_libunwind" = xyes; then
+ AC_DEFINE(HAVE_LIBUNWIND, 1, [Have libunwind support])
+fi
+AM_CONDITIONAL(HAVE_LIBUNWIND, [test "x$have_libunwind" = xyes])
+